Patents Assigned to Liaisons-Electroniques Mecaniques LEM S.A.
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Patent number: 8324883Abstract: The invention relates to a Rogowski-loop current sensor comprising a winding (4) extending between two ends (14, 16) configured to be provided about a primary conductor in which flows a current to be measured by moving said ends away from or towards each other. The sensor further includes a closing mechanism (18) provided at the ends of the winding, and including a body (20) having a high magnetic permeability and extending between said ends when the loop is closed.Type: GrantFiled: June 18, 2008Date of Patent: December 4, 2012Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Pierre Turpin
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Publication number: 20120139527Abstract: Electrical current transducer comprising a measuring circuit (6) and an inductor (4) for measuring a primary current IP flowing in a primary conductor (2), the inductor comprising a saturable magnetic core (10) made of a highly permeable magnetic material and a secondary coil (12) for carrying an alternating excitation i configured to alternatingly saturate the magnetic core, the coil being connected to the measuring circuit. The measuring circuit is configured to measure a mean value of the excitation current in the secondary coil and determine therefrom a value of the primary current for small current amplitudes, the measuring circuit being further configured for evaluating the frequency of the excitation current i and determining therefrom the value of the primary current for large currents.Type: ApplicationFiled: August 10, 2010Publication date: June 7, 2012Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Wolfram Teppan, Hiroshi Obata, Yori Hatakeyama
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Publication number: 20120126789Abstract: The invention relates to a Rogowski-loop current sensor comprising a winding (4) extending between two ends (14, 16) configured to be provided about a primary conductor in which flows a current to be measured by moving said ends away from or towards each other. The sensor further includes a closing mechanism (18) provided at the ends of the winding, and including a body (20) having a high magnetic permeability and extending between said ends when the loop is closed.Type: ApplicationFiled: June 18, 2008Publication date: May 24, 2012Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Pierre Turpin
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Patent number: 7969140Abstract: A magnetic field sensor comprises a magnetic field sensing cell and a magnetic shield comprising at least two parts separated by an air-gap and surrounding the magnetic field sensing cell positioned in a cavity of the magnetic shield.Type: GrantFiled: July 7, 2009Date of Patent: June 28, 2011Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Wolfram Teppan
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Patent number: 7965162Abstract: An electrical current sensor comprises a magnetic circuit with an air-gap, a magnetic field sensor positioned in the air-gap, and a secondary coil surrounding a branch of the magnetic circuit. The magnetic circuit comprises at least two parts (18, 20) that are assembled together, a branch portion (45, 46) of each part being insertably received in a central cavity of the secondary coil in an axial direction (A). The air-gap (30) is arranged between overlapping branch portions of each magnetic field circuit part.Type: GrantFiled: July 6, 2005Date of Patent: June 21, 2011Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Marc Schaerrer, Pascal Morel, Bernard Richard, Pierre Cattaneo
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Publication number: 20100265027Abstract: Magnetic circuit comprising a gap bridging element made of a non-magnetic metal and a wound magnetic core comprising a plurality of stacked concentric ring layers of magnetic material having a high magnetic permeability. The magnetic core has a gap extending through a section of the stacked concentric ring layers of magnetic material, wherein the bridging element is welded to a lateral face of the wound magnetic core on either side of the gap. Welding connections between the bridging element and the magnetic core extend across the stacked concentric ring layers.Type: ApplicationFiled: February 23, 2010Publication date: October 21, 2010Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Sylvain Demolis, Pierre Mariano Benedetti, Thierry Didier Chenavard
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Publication number: 20100259248Abstract: An electrical current sensor (2) comprising a magnetic core (6) with an air gap (14), a magnetic field detector (8) positioned at least partially in the air gap, and a conductive mounting element (10). The mounting element comprises at least first and second fixing extensions (56) extending between opposed outer faces of the magnetic circuit, and a bridge portion (34) interconnecting the fixing extensions and spanning across the air gap. The bridge portion comprises an electrical terminal (42) in electrical contact with a grounding pad (24) of the magnetic field detector.Type: ApplicationFiled: December 17, 2008Publication date: October 14, 2010Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Arnaud Labbe
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Patent number: 7746065Abstract: A magnetic field sensor comprises a reference magnetic field generator (8), a magnetic field sensing cell (6) including Hall effect sensing elements (12), and a signal processing circuit (4) connected to the output (11) of the magnetic field sensing cell and comprising one or more feedback lines (27, 28) for correcting error fluctuations in the transfer characteristic of the magnetic field sensor. The reference magnetic field generator is adapted to generate a frequency modulated reference magnetic field. The signal processing circuit further includes a modulator connected to the magnetic field sensing cell, adapted to modulate the output signal thereof at a frequency different from the modulation frequency of the reference magnetic field generator.Type: GrantFiled: September 14, 2005Date of Patent: June 29, 2010Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Marc Pastre, Hubert Blanchard, Maher Kayal
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Publication number: 20100097049Abstract: Open-loop electrical current sensor (1) for measuring the electrical current flowing in a primary conductor, comprising a magnetic circuit (3) with an air-gap (4), and a magnetic field sensing device (5) positioned at least partially in said air-gap. The magnetic field sensing device comprises a circuit board (7), a first magnetic field detector (8) mounted on the circuit board, and a second magnetic field detector (11). The second magnetic field detector comprises a conductive coil formed on the circuit board, the output signals of the first magnetic field detector and the second magnetic field detector being adapted for connection to a signal processing circuit (6) generating an output signal representative of the primary electrical current.Type: ApplicationFiled: February 22, 2008Publication date: April 22, 2010Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Gerard Lepine, Vinh Tho Vo
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Patent number: 7667452Abstract: Detector circuit for measuring relatively strong currents including a main current transformer (1) and two substantially identical auxiliary current transformers (2, 3) where a main current (I1) induces magnetomotive forces in said main current transformer (1), said magnetomotive forces being counteracted by magnetomotive forces induced by a compensating current (i1) while at the same time the two auxiliary transformers (2, 3) are magnetised in antiphase by means of a square wave/modulation signal. Furthermore the detector circuit includes a synchronous rectifier for generating an adjusting signal for the compensating current (i1). According to the invention a compensating current is used for measuring current in a common winding (L3) surrounding the main transformer as well as the auxiliary transformers while at the same time a possible error signal in the shape of a voltage difference between the auxiliary transformers is used to adjust the compensating current (i1) by means of a negative feedback loop.Type: GrantFiled: November 4, 2005Date of Patent: February 23, 2010Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Andreas Marcussen
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Patent number: 7659709Abstract: An electric current sensor having a housing, magnetic circuit with a magnetic core, and a magnetic field detector with a detection cell, positioned in an air gap between ends of the core. The core is made of a non-laminated magnetic material, and the magnetic circuit has a strap made of non-magnetic material welded to the core at each side of the air gap. The magnetic field detector has a support plate on which the detection cell is mounted. The plate has a recess, opposition the detection cell, which houses one end of the magnetic circuit.Type: GrantFiled: November 14, 2007Date of Patent: February 9, 2010Assignee: Liaisons Electroniques-Mécaniques LEM S.A.Inventors: Gerard Lepine, Olivier De Loriol, Gilles Moret, Thierry Chenavard
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Patent number: 7492145Abstract: An electric current sensor having a housing, magnetic circuit with a magnetic core, and a magnetic field detector with a detection cell, positioned in an air gap between ends of the core. The core is made of a non-laminated magnetic material, and the magnetic circuit has a strap made of non-magnetic material welded to the core at each side of the air gap. The magnetic field detector has a support plate on which the detection cell is mounted. The plate has a recess, opposition the detection cell, which houses one end of the magnetic circuit.Type: GrantFiled: January 20, 2004Date of Patent: February 17, 2009Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Gerard Lepine, Olivier De Loriol, Gilles Moret, Thierry Chevanard
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Publication number: 20080231255Abstract: A three-phase current sensor for measuring currents (IPH1, IPH2, IPH3) running in three conductors of a three-phase conductor system comprises a first magnetic measuring device (D1) and a second magnetic measuring device (D3). Each magnetic measuring device comprises a magnetic circuit provided with at least two interleaf gaps and a magnetic field sensor arranged in each interleaf gap. The magnetic measuring devices (D1, D3) are positioned on both sides of a central conductor or cavity, thereby enabling a central conductor to be inserted in such a way that one of three phases of the conductor system is formed.Type: ApplicationFiled: July 28, 2006Publication date: September 25, 2008Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Gerard Lepine, Arnaud Labbe, Vinh Vo
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Publication number: 20080094068Abstract: The electrical measuring apparatus (17) and temperature sensing apparatus minimises the number of connections required for each contact (30, 31) of a battery (18). The present invention measures the core temperature of the battery (18) which is useful in monitoring the health of the battery (18). The apparatus comprises first connection means to connect to the first contact (30) of the battery (18) and second connection means to connect to the second contact (31) of the battery (18). The apparatus includes a thermistor (36) which connects in series with one lead (32) of the connecting means. Accordingly, the apparatus does not require the temperature sensor (36) to be independently connected to the battery (18).Type: ApplicationFiled: November 2, 2005Publication date: April 24, 2008Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Nigel Scott
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Publication number: 20070247141Abstract: A magnetic field sensor comprises a reference magnetic field generator (8), a magnetic field sensing cell (6) including Hall effect sensing elements (12), and a signal processing circuit (4) connected to the output (11) of the magnetic field sensing cell and comprising one or more feedback lines (27, 28) for correcting error fluctuations in the transfer characteristic of the magnetic field sensor. The reference magnetic field generator is adapted to generate a frequency modulated reference magnetic field. The signal processing circuit further includes a modulator connected to the magnetic field sensing cell, adapted to modulate the output signal thereof at a frequency different from the modulation frequency of the reference magnetic field generator.Type: ApplicationFiled: September 14, 2005Publication date: October 25, 2007Applicant: Liaisons Electroniques-Mecaniques LEM S.A.Inventors: Marc Pastre, Hubert Blanchard, Maher Kayal
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Patent number: D505870Type: GrantFiled: June 1, 2004Date of Patent: June 7, 2005Assignee: Liaisons-Electroniques Mecaniques LEM S.A.Inventor: Guy Vuillermoz
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Patent number: D506153Type: GrantFiled: January 28, 2004Date of Patent: June 14, 2005Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Pascal Morel
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Patent number: D510881Type: GrantFiled: August 27, 2004Date of Patent: October 25, 2005Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Pascal Morel
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Patent number: D511112Type: GrantFiled: December 18, 2003Date of Patent: November 1, 2005Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Hiroto Takada
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Patent number: D496872Type: GrantFiled: August 21, 2003Date of Patent: October 5, 2004Assignee: Liaisons Electroniques-Mecaniques LEM S.A.Inventor: Jean-Pierre Edmond